Lubricating composition



Patented July 14, 1953 UNITED STATES PATENTI OFFICE LUBRICATING COMPOSITION poration of Delaware No Drawing. Application March 14, I949,

Serial N0. 81,404

10 Claims. 1

This invention relates to lubricants particularly suitable for lubrication under extreme operating conditions such as under extreme pressure and wear conditions.

It is well known that the high pressure occurring in certain types of gears and bearings may cause a film of lubricant to rupture with consequent damage to the machinery. It has been shown that base lubricants, such as mineral oil and/orsy'nthetic oil, can be improved with regard to their protective effect particularly on rubbing surfaces by the addition of certain substances, so that excessive wear, scuffing and seizure, which normally follow a break in the film of lubricant, can thus be prevented even under the most unfavorable pressure and speed conditions. Oils possessing this highly desirable property are called extreme pressure lubricants.

It is known that certain elements or compounds of elements of the type of chlorine, sulfur, phosphorus, and lead in combination with sulfur, are capable of imparting extreme pressure properties to lubricants, which may be lubricating oils and greases, when blended therewith. Among the compounds heretofore used are notable the lead soaps in combination with sulfur, phosphoric acid esters, free or loosely bound sulfur, and certain chlorinated organic compounds.

It has now been discovered that lubricants in general can have extreme pressure and anti-wear properties imparted to them by introducing into said base lubricants a complex compound, which complex consists of at least two dissimilar metal compounds which may be organic or inorganic, which may be physically admixed or chemically coupled with non-metallic organic compounds, such as the alkyl, aryl, alkoxy, aroxy, alkyl mercapto, aryl mercapto, alkyl seleno, aryl seleno, alkyl telluro and/or aryl telluro derivative of a non-metallic element of the 5th and 6th group, right-hand side, of the periodic system of elements. The non-metallic elements of these groups are phosphorus, arsenic, antimony oxygen, sulfur, selenium and tellurium. One or several of the organic radicals may contain substituent groups such as NI-I2, N02, NO, N=NO, CN, SCN, OH-, SH, SeH, TeH, SOsH, CXXH wherein the Xs may be oxygen or elements of the sulfur family or mixtures thereof, and/or a halogen. The general formula of the chemically coupled complex of this invention having at least two dissimilar metals can be represented by the general formula wherein M and M are dissimilar metals er cations each of which forms a compound with same or different radical A; 2 and b are small whole numbers and are the numbers of atomic proportions of M and M which may be an electronegative radical such as an acid radical or an organic radical capable of forming metal organic compounds; at is the sum of the product of the symbols a times the valence of M and b times the valence of M; said portion of the'complex being combined with the organic compound BRy wherein B is a non-metallic element of the 5th and 6th groups, right-hand side of the periodic system of elements in the hydride form; R represents alkyl, aryl, alkoxy, aroxy, alkyl mercapto, aryl mercapto, allyl seleno, aryl seleno, alkyl telluro and/or aryl telluro radicals which may or may not be substituted; 1 is a number of 2 or 3; and 'm and n are integers of 1 and 2 to 8 respectively.

If the complex of this invention is a physical mixture it may be represented by the formulas wherein M and M are dissimilar metals; the symbols A, B and R being the same as defined in Formula I; m is the number of radicals in the compound; a is the number of metal atoms in the compound; n is 2 or 3, and m is preferably not more than 4. The two complexes may be used vin wide proportions such as in the ratio of 1:10

and preferably in the ratios of 1:1 to 1:3.

The following metals represented above by M and M are capable of forming dissimilar metal organic complexes of the type described: copper, silver, zinc, cadmium, mercury, nickel, cobalt, iron, aluminum. Amon the radicals which represent A in the above formulas, the fluoride, chloride, bromide, azide, thiocyanate, sulfate, carbonate, xanthogenates, the fatty acid radicals, phenoxy, ethoxy radicals and the like.

Preferred organic compound BR are the alkyl, alkenyl, cycloalkyl and aryl oxides, sulfides, selenides and tellurides of 4 to 20 carbon atoms, such as di-ethyl, dipropyl, dibutyl, diamyl, dicetyl, ethyl propyl, ethyl isobutyl, methyl cetyl, ethyl cyclohexyl, ethyl phenyl, isopropyl phenyl, cetyl phenyl, diphenyl, phenyl tolyl, dibenz-yl oxide, sulfide, selenide and telluricle. Also the compound BR may represent the alkyl, aryl, alkoxy, aroxy, alkyl mercapto, aryl mercapto, as well as the seleno or telluro analoge of phosphines, phosphite, arsenite, arsine, stibine and antimonites of 3 to 30 carbon atoms. Specific compounds are: trimethyl, el-imethyl ethyl, methyl ethyl propyl,

3 methyl ethyl cetyl, dibutyl cetyl, triethyl, tripropyl, tri-isopropyl, tributyl triamyl, tricetyl, dimethyl butyl, methyl diphenyl, diethyl benzyl, triphenyl, tritolyl, phosphines, phosphites, arsenite, arsine, stibine, and antimonites.

Of the two types of complexes referred to above the chemically coupled complex having at least two dissimilar metals as represented by Formula I is preferred to the physical mixtures of two or more simple complexes as represented by Formulas II and III as additives for lubricating compositions.

To more clearly illustrate the present invention, the following examples are presented. It is to be understood, however, that various modifications can be resorted to without departing from the spirit of the invention.

GROUP I CHEMICALLY COUPLED COM- PLEXES EXAMPLE I cuprous chloride-stannous chZorz'cle-tributyl phosphite complex EXAMPLE II Cupric fluoride-stannous chloride-tributyl phosphite complex Complexes involving three molar ratios of cupric fluoride to stannous chloride were prepared with tributyl phosphite under conditions as outlined in the table below. The complexes thus formed were soluble in oils, greases and fuel compositions.

TABLE A [Reaction conditions: Approximately 2 hours of stirring under nitrogen at about 100 0.]

Cupric Stannous trlbutyl mold Color and fluoride chloride phosphlte Appearance 0.057 0. 05 0. 4 1. 4468 pale amber liquid. 0. 070 0.025 0. 4 1. 4410 pale green liquid. 0.013 075 0. 4 1. 4481 pale amber liquid.

EXAMPLE III Silver chloride-cuprous chloride-tributyl phosphite complex A number of these complexes were prepared in which the molar ratio of the two chlorides was varied. The reaction was carried out under the conditions outlined in Table B. The complexes were stable, non-corrosive and oil-soluble.

TABLE B 1 Reaction conditions: Approximately 2 hours of stirring under nitrogen at 140 to 160 0.]

Silver Cuprous Tributyl mO/d Color and chloride chloride phosphite Appearance 0. 0. 025 0. 4 1. 4571 pale yellow liquid. 0. 05 O. 05 0.4 1.4624 Do. 0.15 0. 05 0.8 1.4604 Do. 0. 05 0.15 0.8 1. 4621 Do.

4 EXAMPLE IV Silver chlo ride-stcmnous chloride-tributyl phosphite complex This complex was formed under the conditions outlined in Table C. The complex was stable, non-corrosive and oil-soluble. 1

TAB LE 0 [Reaction conditions: Approximately 2 hours stirring under nitrogen at room temperature] Silver ehZorz'de-manganous chloride-tributyl phosphite complex Approximately 0.05 mol of silver chloride, 0.05 mol of manganous chloride and about 0.4 mol of tributyl phosphite were heated for about 10 to 20 minutes at about C. The mixed complex contains both silver and manganese in the molecule and has a refractive index (n ZO/d) of 1.4516. It is stable, non-corrosive and oil-soluble.

EXAMPLE VI C'upric bromide-manyanous chloride-tributyl phosphite A mixture of cupric bromide (0.035 mol) manganous chloride (0.035 mol) and tributyl phosphite (0.28 mol) were mixed together at room temperature and thereafter the temperature was increased to 5075 C. and the reaction was maintained at this temperature until a clear product resulted. The final product was stable, oil soluble and had a refractive index of (n ZO/d) of 1.4464.

, EXAMPLE VII Cup'rous ioclide-manganous chloride tributyl p'hosphz'te complex A mixture of cuprous iodide (0.05 mol), manganous chloride (0.005 mol) and tributyl phos phite (0.4 mol) was stirred at room temperature. An exothermic reaction set in and the temperature rose to about 40 C. The mixture was heated with stirring at about 100 C. for about /2 hour. The final mixed complex had a refractive index (n ZO/d) of 1.4575, it was stable, non-corrosive and oil-soluble.

EXAMPLE VIII cuprous chloride-stannous chloride tributyl arsenite complex A mixture of cuprous chloride (0.02 mol) stannous chloride (0.02 mol) and tributyl arsenite (0.4 mol) were mixed together and heated in a nitrogen atmosphere at ISO- C. for about 4 hours. The material was cooled, filtered and the product obtained was a dark brown oil soluble liquid which had a refractive index of (n 20/d) of 1.4692...

a c-cums Cuprous chZoride-stannous chloride trz'buty'l anti-- monite complex A mixture of vcuprous chloride (0.003 mol) stannous chloride (0.003 mol) and tributyl antimonite (0.06 mol) were'mixed together and heated under reflux conditions at a temperature ranging from 160-180 C. under an inert atmosphere for about 5 hours. The material was cooled, filtered and the product obtained was an oil soluble blackish brown liquid which had a refractive index (n 20/d) of 1.5078.

EXAMPLE X Mixed metal complexes involving cobaltous chloride and stannous chloride and tributyl phosphite with (a) stannous chloride, (1)) cuprous bromide and (c) manganous chloride.

The conditions for carrying out the reaction and properties of the final product are given in the table belowf TABLE ID "Trihutyl' Oobaltous p v Colorami Chloride z 'if g gfig m/Zod sAppear- (mol) 1mm) anoe 05 0 05 0. '4 dark blue. 0.05 cuprous bromide 0.4 1. 449 dark (O. 025). green liquid. 0.05 manganous chlo- 0.2 1. 468 dark ride (0 05). bluegreen liquid. 0.05 0.05 0. 4 1. 455 Do.

Other examples of mixed complex compounds of this invention are:

Cuprous chloride-stannous chloride-tributyl phosphine silver chloride-manganous chloride-tributyl phosphine I Cobaltous chloride-stannous chloride-tributyl phosphine Cuprous chloride-stannous chloride-triethyl arsenite v Cuprous chloride-stannous chloride-tributyl antimonite Cuprous bromide-silver bromide-triphenyl phosphite Stannous bromide-m'anganous bromide-dibutyl phenyl phosphite Stannous bromide-manganous bromide tripropyl phosphine Cuprous sulfate-stannous phosphine silver ohloride-stannous sulfate-di-butyl selenide Cuproacetyl acetone-stannous acetyl acetone-trimethyl phosphite Cuprous chloride-silver chloride-di-n-butyl sulfide Cupro ureum-cobaltous ureum-triethyl phosphite Cupro phenolate-silver phenolate-triethyl phosphine Cupro phenolate-silver phenolate-triethyl 'arsenite Cupro phenolate-silver phenolate-triethyl arsine Cuproacetyl amide-manganous 'cetyl amine-tributyl phosphite chloride-tripropyl Cupro cyclopentadiene-manganous cyclopentadiene tributyl phosphite Silver iodide-cobaltous iodide-di-n-but-yl telluride silver chloride-cuprous chloride-trimethyl arsenite 'Cobaltous chloride-stannous butyrate-trimethyl chloride-ethylene Silver chloride-cupro chloride-diisobutenyl sulfide Nickel oleate-silver oleate-tributyl phosphite Nickel oleate-silver oleate-tributyl phosphine Cupro ole'ate-cobaltous oleate-dioctyl selenide Cupro oleate-cobaltous oleate-methyl cetyl selenide Cupro urea-silver urea-tributyl phosphite Cupro urea-silver urea-tributyl antimonite Cupro urea-silver urea-triphenyl phosphite Cupro-n-propyl mercaptide-manganous n-propyl meroaptide Cupro-n-propyl mercaptide-tripropyl phosphine Cobaltous chloride-stannous chloride-cetyl mercaptan Cobaltous arsenite chloride-cuprous bromide-triphenyl The above examples of mixed metal complexes of this invention may be chemically coupled or the. complexes may be physical mixture of two simple complexes having dissimilar metals.

Still other types of complexes which may be used as improving agents in compositions of this invention wherein the mixed dissimilar metal complex in addition contains dissimilar organic portion of the complex and may be represented by the general formula:

wherein M, M, A, B, R, a, b, m, m, y and n are the same as in Formula I and D is a non-metallic "element of the 5th and 6th group, right-hand side, of the periodic system of elements in the hydride form but dissimilar from B which also represents the same metallic elements. Examples of such mixed metal-mixed organic complexes may be represented by the following specific examples Cuprous chloride-stannous phosphite-tributyl phosphine Silver chloride-cuprous chloride-tributyl phosphite-tributyl phosphine Silver chloride-stannous chloride-tributyl phosphite-tributyl phosphine Silver chloride-manganous phosphite-tributyl phosphine chloride-tributyl ohloride-tributyl A chloride-tributyl phosphite-tributyl phosphine chloride-triethanol chloride-cetyl If desired, mixed metal complexes of this invention may be produced in solution of a suitable solvent such as a lubricating oil, by dissolving or suspending, first one component in the solvent, then adding the other components to the solution or adding all of the compounds at one time and thereafter agitating the mixture at a reaction temperature which may vary from room temperature to 200 C. and preferably from 40 C. to 110 C. until the complex formation is completed.

The amount of the mixed metal complexes which is generally used to impart extreme pressure properties may vary from a fraction of 1% to about However, if desired amounts of as high as to may be used, but the preferred range in most cases varies from 1% to 10%.

Base oils to which mixed metal complexes of this invention are added may be selected from a variety of natural oils such as paraffinic, naphthenic, and mixed base oils having a viscosity range, such as 90 at 100 SUS up to 250 at 210 F. SUS. In addition synthetic oils may be used such as polymerized olefins, alkylated aromatics; polymers and copolymers of alkylene glycols and alkylene oxides; organic esters of dibasic acid, eL'g. Z-ethyl hexyl sebacate, dioctyl phthalate; other esters, e. g. ethyl ricinoleate, butyl benzoate, trioctyl phosphate, polymeric tetrahydrofuran; polyalkyl silicone polymers, e. g. dimethyl silicone polymer, other silicone polymers; HzS- adducts of unsaturated ethers and thioethers, e. g. H28 adduct of dialkyl ether. Mixtures of natural and synthetic oilscan be used. Under certain conditions of lubrication minor amounts of a fixed oil such as castor oil, lard oil, and the likemay be admixed with a hydrocarbon oil and or synthetic oil.

Mono metal complexes similar to the dissimilar polymetal complexes of this invention are well known in the art. However, these monometal complexes such as silver chloride-tributyl phosphite, complex or cuprous chloride-dibutyl sulfide complex and the like are highly unstable and extremely corrosive. On the other hand, the dissimilar polymetal complexes of the present invention are stable and are non-corrosive. Another point of marked difierence between a monometal complex and a dissimilar polymetal complex of this invention is the wider applicability to which complexes of the present invention can be put to use.

In general, these metal complexes are capable of preventing seizure and Wear by plating out on if any beneficial properties at low temperature lubrication. However, with judicial selection of the metals in complexes of the present invention a lubricant containing said complex will possess beneficial properties over a wide temperature range. Thus; for example, with a silvertin complex of tributyl phosphite the silver portion of thecomplex imparts its beneficial properties at one temperature range while the tin portion of the complex imparts its beneficial properties at another temperature range. In cases where the metals operate at about the same temperature range a synergistic effect appears to take place as will be clearly shown by the data presented hereinbelow.

The metal portion of the complex is not the only part of the complex which aids in lubrication. The anion-portion of the metal compound such as the halide, sulfate, xathogenate and the like as well as the organic portion of the complex such as the phosphites, arsenites, etc., may also under certain conditions either react with or form on contacting metal surfaces covered with their metallic film, additional protective films comprised of phosphides, phosphites, halides, etc. of the metals of low heat strength, which prevent wear,' corrosion and the like. Under certain conditions either the anion portion or the organic portion of the complex is much more reactive than the metal portions of the complex and in such cases a soft metal film is not formed but rather a halide or phosphite coating which imparts the desired propertiesto the lubricant.

[To illustrate the pronounced improvement obtained in lubricating compositions by the addition of dissimilar olymetal complexes of this invention the following test data is given:

Compositions of this invention were evaluated as extreme pressure agents by the use of the Four-Ball extreme pressure lubricating tester similar in principle to the Boerlage apparatus described in themagazine Engineering, volume 136, Julyv 14, 1933. This apparatus comprises four steel balls arrangedin pyramid formation. The top ball is rotated by spindles against the three bottom balls which are clamped in a stationary ball holder. The ball are immersed in the composition to be tested. Tests were run under conditions indicated in the table and compared with other outstanding extreme pressure agents.

.Four-Ball E. P. lubricant testevon additives in SAE oil 'IFixed conditions: 1 minute tests at 1500 R. P. M., steel on steel.]

In order to compare the anti-corrosive properties-of complexes of this invention, polished strips of high-carbon steel heat-treated to a Rockwell hardness of C35C40 were partially immersed in compositions of this invention and in other compositions as noted in the table below and the compositions containing the metal strips.

were heated at C. for 24 hours.

The resultsof the. test wereas follows-.2

Dissimilar polymetal complexes of this invention in addition to being valuable constituents in various lubricating compositions such as heavy duty oils, motor oils, diesel oils, aviation oils, turbine oils, are valuable additives in grease compositions such as the alkali, alkaline earth and heavy metal soap greases, in which the base may be a mineral oil or a synthetic oil such as organic esters (di-ethyl hexyl sebacate), silicone polymers (dimethyl silicone polymer), alkylene oxide and glycol polymers and copolymers as well as mixtures of said hydrocarbon and synthetic oil with or without the additional presence of a fixed fat or oil'such as castor oil and the like. Soaps and mixtures of soaps for use in grease compositions which are particularly preferred when in combination with complexes of this invention are the lithium, sodium, calcium, barium,.strontium, lead, aluminum soap of free fatty acids or their glycerides, said fatty acids being saturated, unsaturated and/or hydroxy substituted fatty acids having from to carbon atoms. Instead of using soap as the gelling agent for making grease any gelling agent may be used such as inorganic silica or alumina gels,.colloidal carbon and the like. Mixtures of soap and inorganic or organic gelling agents may also be used in making grease.

Additives of this invention may also beused in damping and hydraulic fluids, insulatingoils, heat transfer mediums, rubber compositions of the natural or synthetic'type, coating compositions, metal working lubricants, insecticidalcompositions and the like.

Because of their synergistic effect the dissimilar polymetal complexes of this invention can be combined with other additives which may be present in lubricants, greases, hydraulic fluids, etc. Among the specific additives which can be used are oil-soluble detergents which include oil-soluble salts of various bases with detergent forming acids. Such bases include metal as well as organic bases. Metallic bases include those of the alkali metals, Cu, Mg, Ca, Sr, Ba, Zn, Cd, Al, Sn, Pb, Cr, Mn, Fe, Ni, Co, etc. Organic bases include various nitrogen bases as primary, secondary, tertiary and quaternary amines.

Examples of detergent forming acids are the various fatty acids of, say 10 to 30 carbon atoms, Wool fat acids, paraifin wax acids (produced by oxidation of paraffin Wax) chlorinated fatty acids, aromatic hydroxy fatty acids, paraffin wax benzoic acids, various alkyl salicylic acids, phthalic acid monoesters, aromatic keto acids, aromatic ether acids, diphenols as di- (alkylphenol) sulfides and disulfides, methylene bis a1- kylphenols; sulfonic acids such as may be produced by treatment of; alkyl aryl hydrocarbons or high boiling petroleum oils with, sulfuric acid; sulfuric acid monoesters; phosphoric, arsonic and antimony acid mono and diesters, including the corresponding thio phosphoric, arsonic and antimony acids; phosphonic and arsenic acids and the like.

Additionaldetergents: are the alkaline earth phosphate. diesters, including the thiophosphate diester; the alkaline earth diphenolates, specifically theucalcium and barium salts of diphenol mono and poly sulfides.

Non-metallic detergents include compounds such asthe phosphatides such as lecithin and cephalin, certain fatty oils as. rapeseed oils, voltolized fatty or mineral oils and the like.

An excellent metallic. detergent for the pres ent purpose the calcium. salt of oil-soluble petroleum sulfonic acids. Fhis may be present advantageously inthe. amount of about 0.025% to 0.2% sulfate ash. Also alkaline metal salts of alkyl phenol-aldehyde condensation reaction products are excellentdetergents.

Antioxidants com-prise several types, for ex-.

ample, al-kyl phenols: such as 2,4,6-trimethyl phenol, pentamethylphenol, 2,4-dimethyl-6-tertiary butylphenol, 2,4-dimethyl-6-octylphenol, 2,6 di tertiary buty-l 4 methylphenol, 2,4,6- tritertiary-butyl phenol and the like; aminophenol's as benzyl aminophenols; amines such as dibutylphenylenediamine, diphen-ylamine, phenyl' beta naphthylamine, phenyl alphanaphthyl amine, dinaphthylamine.

Corrosion inhibitors or anti-rusting compounds may also be present such as dicarboxylic acids of 1-6- andmore carbon atoms; alkali metal and alkaline earth salts of sulfonic acids and fatty acids, organic compounds containing an acidic radical in close proximity toa nitrile, nitro or nitroso group (e. g. alpha-cyano stearic acid).

Extreme pressure agents which may be used comprise-t esters or phosphorus acids such as triaryl, alkyl hydroxy aryl, or' aralkyl phosphates, th-iophosphates or= phosphites and the like; neutral aromatic sulfur compounds of relatively high boiling temperatures such as diaryl sulfides, diaryl' di'sulfides, alkyl aryl disulfides, e; g. diph'erryl sulfide, diphenol sulfide, dicresol sulfide, dixylenol sulfide; methyl butyl diphenol sulfide, dibenzyl sulfide, corresponding diand trisuliides, and the like; sulfurized fatty oils or estersof'fat'ty acids and monohydric alcohols, e. g. sperm oil, jojoba oil, etc.; in which the sulfur is strongly bonded; sulfurized long chain olefins such as may be obtained by dehydrogenation or cracking of wax; sulfurized phosphorized fatty oils or acids, phosphorous acid esters having sulfurized organic radicals, such as esters of phosphoric or phosphorus acids with sulfurized hydroxy fatty acids; chlorinated hydrocarbons, such as chlorinated paraffin, aromatic hydrocarbons, terpenes, mineral lubricating oil, etc.; or chlorinated esters of fatty acids containing the chlorine in position other than alpha position.

Additional ingredients may comprise oil-soluble urea or thiourea derivatives, e. g. urethanes, allophanates, carbazides, carbazones, etc.; polyisobutylene polymers, unsaturated polymerized esters of fatty acids and monohydric alcohols and other high molecular Weight oil-soluble compounds.

Depending upon the additive used and conditions under which it is used, the amount of addi- 1 1i. tive used may vary from 0.01 to 2% or higher. However, substantial improvement is obtained by using amounts ranging from 0.1 to 0.5% in combination with dissimilar polymetal complexes of this invention.

We claim as our invention:

1. An extreme pressure mineral lubricating oil having incorporated therein from 1% to 10% of a complex of silver chloride-cuprous chloridetributyl phosphite with the molar ratio of silver chloride to cuprous chloride being 1 to 1 and the molar ratio of the sum of silver chloride and cuprous chloride to tributyl phosphite being 1 to 4.

2. An extreme pressure mineral lubricating oil having incorporated therein from 1% to 10 of a complex of silver chloride-stannous chloridee tributyl phosphite with the molar ratio of silver chloride to stannous chloride being 1 to 1 and the molar ratio of the sum of silver chloride and stannous chloride to tributyl phosphite being 1 to 4.

3. An extreme pressure mineral lubricating oil having incorporated therein from 1% to 10% of a complex of cuprous chloride-stannous chloride-tributyl phosphite with the molar ratio of cuprous chloride to stannous chloride being 1 to 1 and the molar ratio of the sum of cuprous chloride and stannous chloride to tributyl phosphite being 1 to 4. I

4. An extreme pressure mineral lubricating oil having incorporated therein from 1% to 10% of a complex silver chloride-cuprous chloridetrialkyl phosphite, the alkyl radicals of which contain up to four carbon atoms each, with the molar ratio of silver chloride to cuprous chloride being from 3:1 to 1:3 and'the molar ratio of the sum of silver chloride and cuprous chloride to trialkyl phosphite being 1 to 4.

5. An extreme pressure mineral lubricating oil having incorporated therein from 1% to 10% of a complex silver chloride-stannous chloride-trialkylphosphite, the alkyl radicals of which contain up to four carbon atoms each, with the molar ratio of silver chloride to stannous chloride being from 1:1 to 1:3 and the molar ratio of the sum or" silver chloride and stannous chloride to trialkyl phosphite being 1 to 4,

6. An extreme pressure mineral lubricating oil having incorporated therein from 1% to 10% of a complex cuprous chloride-stannous chloridetrialkyl phosphite, the alkylradicals 'of which contain up to four carbon atoms each, with the molar ratio of cuprous chloride to stannous chloride being 1:1 and the molar ratio of the sum of cuprous chloride and stannous chloride to trialkyl phosphite being 1 to 4.

'7. An extreme pressure mineral lubricating oil having incorporated therein from about 1% to about 10% of a dissimilar metal complex represented by the formula wherein MK and MX are metal halides of dissimilar metals selected from the group consisting of Ag, Cu, Sn, Mn and Co, BB3 is selected from the group consisting of trialkyl phosphites, trialkyl arsenites and trialkyl antimonites, the alkyl radicals in each case containing up to four carbon atoms, the molar ratio of the metal halides MK and MX is from 10:1 to 1:1, and the molar ratio of the sum of the metal halides to the trialkyl compound is from 1:2 to 1:10.

8. The composition according to claim 7, wherein the metal halides are metal chlorides.

9. The composition according to claim 7, wherein the metal halides are metal chlorides and the compound BB3 is a trialkyl phosphite.

10. A new composition which is a dissimilar metal complex represented by the formula wherein MK and MX are metal halides of dissimilar metals selected from the group consisting of Ag, Cu, Sn, Mn and Co, BRais selected from the group consisting of trialkyl phosphites, trialkyl arsenites and trialkyl antimonites, the alkyl radicals in each case containing up to four carbon atoms, the molar ratio of the metal halides MK and MX is from 10:1 to 1:1, and the molar ratio of the sum of the metal halides to the trialkyl compound is from 1:2 to 1:10.

DAVID E. ADELSON. ROY E. THORPE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,149,856 McKone Mar. '7, 1939 2,199,944 Peski May 7, 1940 2,288,288 Lincoln June 30, 1942 2,385,832 Musselman Oct. 2, 1945 OTHER REFERENCES Mann et al.: Chemical Soc. Jour., London, 1940, pages 1230-1235. 

7. AN EXTREME PRESSURE MINERAL LUBRICATING OIL HAVING INCORPORATED THEREIN FROM ABOUT 1% TO ABOUT 10% OF A DISSIMILAR METAL COMPLEX REPRESENTED BY THE FORMULA 